In hospital equipment and practice there exists a need for a device which can regulate the flow of fluid supplied to a life-sustaining apparatus or mechanism. A means for clamping off or stopping the fluid supply flow to the apparatus while maintaining the sterile integrity of the system is a necessary requirement. Such a device must be simple, easy to operate, sterilizable, and relatively accident or tamper-proof. The invention of the present application for an in-line clamp fulfills these requirements.
In its present usage, the clamp is employed on in-line tubing connected to a source of sterilized water or other fluid and to a medical humidifier. The humidifier, in turn, is connected to the patient to provide humidified air for promoting upper respiratory functioning.
It is very desirable to maintain the entire system as sterile as possible to prevent infection. The constant attaching, detaching, and reattaching of a sterilized water source to the humidifier, however, would contribute to a lack of maintenance of that sterile environment.
It is necessary, therefore, for the source of water to be constantly attached to the humidifier. It is also necessary to provide a means for clamping of the flow of water from its source to the humidifier so that only a required amount can be supplied at a given time. The present invention provides such an effective clamping means.
Previous clamps for providing the same function have been standard, flexible metal, pinch-cock type sealing clamps. They are originally supplied in an "open" position, maintained open by a rigid plastic block placed between the jaws and around the tubing. In use the block is removed and the tubing can be clamped off.
To supply the fluid the operator or nurse must manually squeeze the pinch-cock arms apart and keep the tubing open until the desired amount of water is supplied. Given the necessity for a rather large and strong clamping device, this can be a tedious and sometimes awkward operation. In addition, the operator, seeking to avoid the time-consuming process, will sometimes replace the pinch-cock on the retaining block surrounding the tubing. This results in a failure of an appropriate regulation of the water supply and the possibility of over-filling of the humidifier with water.
The present device seeks to avoid these problems by providing an in-line clamping means which is normally maintained in a closed position by means of a crimped or kinked tubing offset, but in-line with the source of sterilized water. In operation, the operator manually opens the clamp, permitting the water to flow into the humidifier. It is much more difficult, however, for the clamp to be maintained open without the operator's attention.
In addition, the physical difficulties in using the previous pinch-cock clamp are overcome by the relative ease of operation in the present clamp.
Clamping devices involving a kinking of tubing mechanism are known in the art. Examples would include:
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Most of these clamping devices while using a kinked or crimped mechanism format for sealing off the fluid flow, also employ an additional device to mantain the crimp in a closed position.
The clamp of the present invention is maintained normally closed without the use of any external device, taking advantage of the natural kinking action of the tube in the clamp caused by the position in which it is affixed to a fluid directing member attached to the supply tubing. This has the obvious advantage over the device-crimped clamps in that it is not susceptible to accidental opening by bumping or malfunction which would permit unwanted fluid flow through the device. There must be in the present instance an affirmative, intentional opening of the clamp by the operator or else it will remain sealed closed.